It is common to protect and beautify the outside of a building by attaching a matrix of panels to the outside of the building, but spaced from the outside of the building by a support structure. These systems are typically called Rain Screen Wall Cladding Systems, Pressure-Equalized Rain Screen Wall Cladding Systems, or simply Rain Screens. The panels protect the outside of the building from the direct effects of weather, and the spacing between the panels and the outside of the building enhance the weather-protecting features, prevent moisture accumulation between the panels and the outside of the building, and provide an insulating layer.
Currently available rain screen systems suffer from a number of performance features that are not always optimum.
First of all, many of the currently available rain screen systems do not allow highly efficient and effective installation of the systems on the buildings, and do not allow highly efficient removal and reinstallation of panels as necessary for maintenance.
Many currently available rain screen systems allow too much rain into the spacing between the outer panels and the outer wall of the building. Sometimes this is caused by failure of the various sealing mechanisms between and around the panels.
In general, water leakage into the space between the rain screen and the building, the building envelope, is driven by five forces: kinetic forces, gravity, surface tension, capillarity, and pressure differentials. Any combination of these forces can be acting on water entering the building envelope. The goal of a rain screen design is to eliminate or minimize their effects. Kinetic forces refer to the horizontal velocity that wind-driven rain drops possess. The momentum can carry them directly through sufficiently sized openings into the envelope interior. The actual rain screen cladding serves to keep most of this water out of the system. Gravity, capillarity, and surface tension can all be combated with appropriately design flashing or drip edges. Pressure differences between the cladding exterior and interior generated by mechanical systems, stack effects, and winds, also act to force or draw water through any openings. Pressure equalized systems are designed specifically to resist this mechanism of leakage and is an important characteristic of a well-designed rain screen system.
Thus, some rain screen systems tend to draw water into the space, because pressure differentials between the outside of the panels (high pressure) and the space between the panels (low pressure) caused by wind and the aerodynamics of the rain screen system, can actually draw water into the space between the panels in the wall. Attempts to design the rain screen systems to minimize this pressure differential are referred to as pressure equalization systems.
The importance of the pressure equalization ability as caused the suppliers of available rain screen systems to claim the feature of pressure equalization and sometimes those claims are unsubstantiated or exaggerated. As result, the American Architectural Manufacturers Association (AAMA) has established a standard (AAMA 508-7) to define pressure equalization in rain screen wall cladding systems. Not all available rain screen systems, including some that claim pressure equalization, are capable of satisfying that standard.
Furthermore, not all currently available rain screen systems provide rapid and effective drainage of any water that does enter the space between the panels in the building wall.
Finally, not all currently available rain screen systems provide rapid and effective drying of any moisture that accumulates between the panels on the wall.
These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of some embodiments of the present invention to provide a rain screen system that is efficient and effective to install.
It is a further object of some embodiments of the invention to provide a rain screen system that is efficient and effective to maintain.
It is a further object of some embodiments of the invention to provide a rain screen system that provides very effective sealing against rain intrusion.
It is a further object of some embodiments of the invention to provide a rain screen system that provides very effective pressure equalization.
It is a further object of some embodiments of the invention to provide a rain screen system that satisfies the AAMA 508-7 standard.
It is a further object of some embodiments of the invention to provide a rain screen system that provides efficient and effective drainage of water from between the panel and the walls.
It is a further object of some embodiments of the invention to provide a a rain screen system that provides a highly effective chimney effect to dry out any moisture between the panel on the walls.
It is a further object of some embodiments of the invention to provide a rain screen system that is capable of being manufactured of high quality and at a low cost, enjoys minimum installation costs, provides highly effective function, and which is capable of providing a long and useful life with a minimum of maintenance.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.